Air diffusers for use with light troffers



2 Sheets-Sheet l .B i 45 MR w 6 2 37 ET b fl zg 5 \/9 E M 6 m fa mm Nov. 30, 1965 H. E. STRAUB AIR DIFFUSERS FOR USE WITH LIGHT TROFFERS Nov. 30, 1965 H. E. STRAUB 3,220,332

AIR DIFFUSERS FOR USE WITH LIGHT TROFFERS Filed May 14, 1962 2 Sheets-Sheet 2 IN VEN TOR.

HAROLD E. STRAUB United States Patent 3,220,332 AIR DIFFUSERS F01? USE WITH LIGHT TROFFERS Harold E. Straub, Cedar Falls, Iowa, assignor to Titus Manufacturing Corporation, Waterloo, Iowa, a corporation of Iowa Filed May 14, 1962, Ser. No. 194,577 3 Claims. (Cl. 9840) This invention, in general, relates to air diffusers in which the air outlet is a narrow slot or slots. This type of diffuser is used primarily in ceiling structures in or adjacent the marginal edge or edges of a recessed, ceiling, lighting fixture structure.

The air diffusers of the invention may be a top feed, double discharge diffuser unit between the sides of which is mounted the recessed, lighting fixture. They may also be a side feed, single discharge unit adapted to be mounted at one side of the recessed, lighting fixture. The diffuser units have individual volume control means in their diffuser passages and individual, discharge-pattern control means in the discharge passages. The volume control means and the discharge-pattern control means are accessible for adjustable positioning thereof through the air discharge slots of the diffuser. The discharge pattern controller in the air discharge passage functions to vary the air discharge pattern from the narrow slot between a full vertical or downward discharge and a full horizontal or outward discharge.

The generic principles of the invention will be further appreciated from the following description of preferred embodiments of the invention and the illustrations thereof in the accompanying drawings, wherein:

FIG. 1 is a perspective view of a top feed, double slot diffuser of the invention showing its relationship with a light troffer of a recessed, ceiling light fixture with a segment of the outer wall of the diffuser broken away to facilit-ate illustration thereof;

-FIG. 2 is a vertical cross-section of the air diffuser of FIG. 1 taken on section 22 of FIG. 1;

FIG. 3 is an exploded, perspective view of a side feed, single slot diffuser of the invention with portions of one side plate broken away;

FIG. 4 is a vertical cross-section through the middle of the assembled embodiment of FIG. 3; and

FIGS. 5 and 6 are enlarged, cross-sectional views of the outlet end of the air discharge passages of the above embodiments.

Referring first to FIGS. 1 and 2, the air diffuser 1 comprises an inner wall 2 and an outer wall 3 defining a bifurcated air passage structure. The inner wall 2 comprises a cross wall 4, sloping upper side wall segments 5, 6 and vertical, lower side wall segments 7, 8. The side wall segments 5, 7 and 6, 8, when viewed in side elevation, are essentially regular trapezoids which have a shallow bend 9 and are joined along the upper side to the edges of the cross wall 4 by rounded corners 10.

The outer wall 3 comprises side walls 11, 12 which are essentially regular trapezoids. The upper edges of the side walls have round segments 13 joining the side walls to an upper wall 14. Upper wall 14 has a cylindrical neck 15 through which air is supplied to the diffuser from a duct (not shown). The side walls 11, 12 and top wall 14 are spaced from the inner wall 2 to form a main chamber 15 communicating with a pair of side, regular trapezoidal air passages 16, 17 through which the air flows from the main chamber 15. The end of the chamber 15 and sides of passages 16, 17 are closed by the bifurcated end walls made integral with the side walls 11, 12 and top wall 14 and attached to the edges of inner wall 2 when the walls are assembled.

The air is discharged from the diffuser through long, narrow slots 18, 19. The direction of flow of discharged 3,220,332 Patented Nov. 30, 1965 air is controlled by long, narrow vane plates 20, 21 which extend substantially the entire length of passages 16, 17 at a point adjacent to but inwardly from the slots 18, 19. The vane plates 20, 21 are pivotally supported on the outer walls 11, 12 by two or more hinge brackets 22 mounted on outer walls 11, 12 and having curved seats 23 rotatably seating rods 24, 25 on the upper edges of vane plates 25, 21. The vane plates are pivotable between a position wherein they lie approximately flat against the side wall and a position wherein they project into the air stream flowing through passages 16, 17. See FIGS. 5 and 6. There is sufiicient friction between bracket seats 23 and rods 24, 25 to hold the vane plates 20, 21 in the position where they project into the air streams.

The inner wall segments 7, 8 have long, narrow walls 26, 27 at the outlet slots 18, 19, which walls extend the length of the slots 18, 19. The walls 26, 27 project into the air flow path through the passages and cooperate with the vane plates 20, 21, when the latter are pivoted into the air streams in a position as shown in FIG. 5, to direct the air streams laterally outwardly as they are discharged from slots 18, 19.

In the vane plate position as shown in FIG. 5, the air stream impinges upon the upper or outer surface 28 of the vane plate. The air stream is diverted toward the inner surface 29 of the inner wall of the diffuser adjacent the discharge slot. The air stream passing through the discharge slot is diverted laterally outwardly by air impinging upon the upper surface 30 of the narrow wall at the discharge opening. The laterally outward diversion of the discharged air stream is aided further by a low pressure zone 31 created behind and below the vane plate. This low pressure zone causes the discharged air stream to be diverted laterally outwardly as it passes through the discharge slot of the diffuser.

On the other hand, when the vane plate is pivoted to be substantially flat against the outer wall, the air stream is not diverted as it passes through the discharge slot. The discharged stream is, therefore, essentially a direct outward or vertical stream. Air stream discharge patterns between full vertical and full horizontal can be achieved by lesser pivoting of the vane plate into the air stream than is shown in FIG. 5.

The vane plates 20, 21 can be pivoted to the desired position by extending ones fingers or a small instrument through the slots 18, 19 and pressing against the vane plates. The type of desired discharge pattern from the two discharge slots of the same diffuser may be the same or different. The desired pattern depends upon the temerature of the air stream in relation to the room temperature, the size of the room, the location of the diffuser with relation to room walls, partitions, the ceiling height, and the like. The diffusers of the invention are adaptable to give a discharge stream of the desired type for each dis charge slot.

Each passage 16, 17 also has a volume flow rate control plate or damper situated at its upstream side. The volume flow rate controllers are long, narrow plates or dampers 32, 33 arcuately bent about the longitudinal axis so that they will lie substantially flush on the rounded corners 10 of the inner wall 2. These plates are pivotally mounted on the inner wall 2, e.g., by piano hinges 35'. The plates extend substantially across the length of the air passage 15 so that, when pivoted toward the outer wall 3, they may block off a portion or substantially all of the upstream side of passages 16, 17. The hinges 35' have sufficient friction to hold the plates 32, 33 in any position in which they are set.

Each plate 32, 33 has an car 34 to which is pivotally connected at 35 a rod 36. Each rod 36 has an ear 37 at its lower end. A second rod 38 is pivotally connected to each car 37. The lower ends of rods 38 normally rest against the inner wall of lower segments 7 and 8, and their lower ends are near or rest against walls 26 and 27. These lower ends can be reached by fingers or a small tool inserted through slots 18, 19.

By pulling or pushing or either rod 38, the damper 32 and/or 33 can be pivoted to the position giving the desired volume flow through its corresponding passage. The rods 38 can then be reinserted in slot 18 or slot 19 and laid against the inner wall with the tip resting on wall 26 or wall 27, as the case may be.

The continuous, outward fiare of chambers 16 and 17 to the ends of slots 18 and 19, respectively, is necessary if a dual, air flow discharge pattern is to be avoided at the ends of the slots when the diffuser vane plate 20 or 21 is set in the horizontal throw position. Hence, the outward flare to the discharge slots is necessary to provide a horizontal discharge pattern along the entire length of the discharge slot(s). The latter pattern is different from the pattern of diffusers similar in structure but wherein the outward flare of the end walls of passages 16 and/or 17 terminates above the discharge slots 18 and/ or 19 with a vertical or substantially vertical lower end wall segment extending to the end of the air discharge slot(s). In such arrangement, the horizontal throw pattern will be a horizontal discharge stream in the mid-portion of the slot(s) and dual, vertical and horizontal discharge streams at the end or ends of the slot(s where there is a vertical, or substantially vertical, lower end wall segment.

The relationship between the diffuser and a light troffer 40 is shown in FIG. 1. along each side in which flange there is a slot to accommodate the lower end of each diffuser passage 16 and 17. Artifical lighting means, e.g., fluorescent tubes 43 are accommodated inside the light troffer 40, which is fixedly mounted in the ceiling structure (not shown). The cross wall 4 is spaced above the top wall 42 of troffer 40 to allow air circulation and heat dissipation.

The outer walls 11, 12 are shown with shoulders 44. These shoulders are the result of inset of the outer wall upper portions to clear certain types of ceiling suspension systems when installing the diffusers. The walls 11, 12 may be planar, if desired, without change in the operation of the diffusers.

The principles of operation for the embodiment of FIGS. 3 and 4 are the same as the principles of operation of the embodiment of FIGS. 1 and 2. The diffuser in FIGS. 3 and 4 is a single feed, single discharge slot diffuser 46 having a regular trapezoidal outer wall 47 and a corresponding regular trapezoidal inner wall 48. A top wall 49, integral with outer wall 47, is joined to the upper edge 50 of inner wall 48 while outwardly sloping end walls 51 are joined with the sloping side edges 52 of the inner wall.

Air from a supply duct is admitted to the diffuser through a neck 53. Neck 53 is of substantially ovular configuration with flat walls on opposite sides. rate of air passing into and through the diffuser is controlled by the positioning of plate 54. Plate 54 is mounted to swing toward and away from the neck 53 by pivot arms 55, 56, one end of which arms are supported rotatably on the inner surface of inner wall 48 by U-channel brackets 57, 58. The other ends of arms- 55,. 56 are supported rotatably in U-channel brackets 59,

60 on the rear face of'plate 54. Rods 55, 56 have out-- wardly bent ends 61, 62 which can be reached by fingers or small tools inserted through the air discharbe slot 63. The rods can be rotated in brackets 57, 58 to cause the plate 54 to swing toward or away from neck 53. Plate 53 thus serves as a damper to regulate the amount of air admitted to the diffuser through neck 53 by its position relative to the neck 53. The friction between arms 55, 56 and brackets 57, 58 is sufficient to keep the plate in any adjusted position.

The troffer has a flange 41 The diffuser of FIGS. 3 and 4 has a vane 64 extending thereacross. Vane plate 64 is supported rotatably in cradle arms 65 extending through slots in the vane plate. Each cradle arm 65 is a part of a U-bracket 66 which is attached to either or both of the inner wall 48 and outer wall 47.

The vane plate 64 functions in a similar manner to vane plates 20, 21 in controlling the pattern of the discharge stream of the diffuser in providing the patterns shown in FIGS. 5 and 6. The vane plate 64 can be pivoted into the air stream of the diffuser to provide, in coaction with the inwardly-directed strip 67 extending along the discharge slot 63, a horizontal discharge stream.

The outer wall 47 has a recess or groove 68 to accommodate certain types of ceiling suspension structures and may be omitted, if desired, without changing the operation of the diffuser.

It will be seen from FIGS. 1 and 2 that the air flow in the passages 16, 17 of this embodiment is a downward, outwardly spreading flow. As the air passages 16, 17 widen between sloping end walls 18, they also taper inwardly in the other axis between the inner and outer walls 5, 11 and 6, 12. This maintains a substantially uniform, horizontal cross-section in passage 16, 17 so that the air will spread laterally as it flows through the passages. The cross-sectional areas of each passage 16 and 17 is preferably above one-half of the cross-sectional area of neck 15 in order tohave a low pressure loss in the diffuser.

The air flow through the diffuser of FIGS. 3 and 4 is of a'different pattern because of the side feed into the unit. The air spreads laterally and downwardly from the neck 53. Hence, there is an inward taper of the outer wall toward inner wall in the outward or sideward directions from the neck 53 as well as an inward taper of the outer wall toward the inner wall in a vertical, downward direction. The vertical cross-sectional area of the passage immediately adjacent each side of the neck 53 is about one-half the cross-sectional area of the neck 53 for the diffuser operating. with the low pressure loss.

The total area of slots 18 and 19 (FIGS. 1 and 2) and of the slot 63 (FIGS. 3 and 4)-is not more than the crosssectional area of neck 15 or 53, as the case may be, and preferably is somewhat less, in order to obtain a good spreading pattern of the discharged air stream or streams.

The generic invention and the preferred embodiments thereof heretofore described set forth the novel structural features by which the advantages and features of the invention may be achieved. Other embodiments may be constructed within the spirit and scope of the invention as defined in the appended claims.

The invention is hereby claimed as follows:

1. An air diffuser comprising wall means defining a narrow, regular trapezoidal air passage, said wall means including closely spaced, opposed, regular trapezoidal side walls defining the sides of said trapezoidal air passage and sloping end walls joining the sloping edges of said trapezoidal walls, an elongated narrow flange long the longest edge of one of said side walls and-extending toward but terminating short of the corresponding longest edge of the other of said'side walls and defining in the space therebetween a long, narrow, downstream, air discharge slot in the base of said trapezoidal passage, passage means for supplying air to the upstreamportion of said trapezoidal passage, elongated, air-directing means in said trapezoidal air passage adapted to-direct the air stream flowing therethrough towardthe upstream side of said flange substantially along the entire length thereof means pivotally mounting said air-directing means on the other side wall, and said trapezoidal side walls converging toward each other from said passage means in the downstream direction toward said slot.

2. An air diffuser comprising w-al-l means defining 1 6066, narrow, parallel, regular trapezoidal air passages connected at the upstream ends by cross-passage, said wall means for said trapezoid-a1 passages including closely spaced, opposed, regular trapezoidal side walls defining the sides of said trapezoidal air passage and sloping end walls joining the sloping edges of said trapezoidal Walls, an elongated, narrow flange along the longest edge of one of said side walls and extending toward but terminating short of the corresponding longest edge of the other of said side walls and defining in the space therebetween a long, narrow, downstream, air discharge slot in the base of said trapezoidal passage, passage means for supplying air to said cross-passage for flow therefrom laterally into aid trapezoidal passages, elongated, air-directing means in each trapezoidal air passage adapted to direct the air stream flowing therethrough toward the upstream side of said flange substantially along the entire length thereof, means pivotally mounting said air-directing means on the other side wall, and said trapezoidal side walls converging toward each other from said passage means in the downstream direction toward said slot.

3. An air diffuser comprising wall means defining a narrow, regular trapezoidal air passage, said wall means including closely spaced, opposed, regular trapezoidal side walls defining the sides of said trapezoidal air passage and sloping end walls joining the sloping edges of said trapezoidal walls, an elongated, narrow flange along the longest edge of one of said side walls and extending toward but terminating short of the corresponding longest edge of the other of said side walls and defining in the space therebetween a long, narrow, downstream, air discharge slot in the base of said trapezoidal passage, passage means in the upstream portion of one of said trapezoidal side walls for supplying air to the upstream portion of said trapezoidal passage, elongated, air-directing means in said trapezoidal air passage adapted to direct the air stream flowing therethrough toward the upstream side of said flange substantially along the entire length thereof, means pivotally mounting said air-directing means on the other side wall, and said trapezoidal side walls converging toward each other from said passage means in the downstream direction toward said slot and also converging in opposite latenal directions toward the slopping edges of said trapezoidal walls.

References Cited by the Examiner UNITED STATES PATENTS 2,991,708 7/1961 Falk 98-40 3,072,038 1/1963 Phillips 98-40 3,093,058 6/1963 La Vigne et a1 9840 3,126,811 3/1964 Kennedy 98---40 ROBERT A. OLEARY, Primary Examiner.

MEYER PERLIN, Examiner. 

1. AN AIR DIFFUSER COMPRISING WALL MEANS DEFINING A NARROW, REGULAR TRAPEZOIDAL AIR PASSAGE, SAID WALL MEANS INCLUDING CLOSELY SPACED OPPOSED, REGULAR TRAPEZOIDAL SIDE WALLS DEFINING THE SIDES OF SAID TRAPEZOIDAL AIR PASSAGE AND SLOPING END WALLS JOINING THE SLOPING EDGES OF SAID TRAPEZOIDAL WALLS, AN ELONGATED NARROW FLANGE LONG THE LONGEST EDGE OF ONE OF SAID SIDE WALLS AND EXTENDING TOWARD BUT TERMINATING SHORT OF THE CORRESPONDING LONGEST EDGE OF THE OTHER OF SAID SIDE WALLS AND DEFINING THE SPACE THEREBETWEEN A LONG, NARROW, DOWNSTREAM, AIR DISCHARGE SLOT IN THE BASE OF SAID TRAPEZOIDAL PASSAGE, PASSAGE MEANS FOR SUPPLYING AIR TO THE UPSTREAM PORTION OF SAID TRAPEZOIDAL PASSAGE, ELONGATED, AIR-DIRECTING MEANS IN SAID TRAPEZOIDAL AIR PASSAGE ADAPTED TO DIRECT THE AIR STREAM FLOWING THERETHROUGH TOWARD THE UPSTREAM SIDE OF SAID FLANGE SUBSTANTIALLY ALONG THE ENTIRE LENGTH THEREOF MEANS PIVOTALLY MOUNTING SAID AIR-DIRECTING MEANS ON THE OTHER SIDE WALL, AND SAID TRAPEZOIDAL SIDE WALLS CONVERGING TOWARD EACH OTHER FROM SAID PASSAGE MEANS IN THE DOWNSTREAM DIRECTION TOWARD SAID SLOT. 